WA Labor’s biggest union donor threatened to withdraw financial support for the political party unless the State Government cut shopping hours this Christmas.

The Shop, Distributive and Allied Employees Association, which has 23,000 members in retail and contributes about $300,000 a year to WA Labor, issued the ultimatum as a row with the Government over trading hours boiled over earlier this year.

This week, Premier Mark McGowan came under fire from big retailers and leading businessmen after cutting 15 hours from the additional time granted for Christmas shopping by preventing shops from opening at 7am until December 17.

The Weekend West can reveal the decision came after the SDA warned Mr McGowan it would stop fundraising and campaign donations unless the cuts to shopping hours were made.

“Our frustration stemmed from the fact that the Labor Party had simply chosen to do what the Liberal Party had done,” SDA secretary Peter O’Keeffe said.

VideoEconomists say the decision will hurt workers big and small as well as retail workers and WA shoppers.

“We had had a number of meetings and we, of course, could never agree. I decided to bring it to a head.

“And then I had a conversation with Mark where I had to put the union’s case as emphatically and aggressively as I could, which I did.”

But the Government’s decision brought a rebuke from the Chamber of Commerce and Industry and Rob Scott and Richard Goyder, the current and former chiefs of retail giant Wesfarmers.

Asked about the union’s threats, Mr McGowan confirmed there was a “robust” discussion with Mr O’Keeffe but could not recall a warning about funding being stopped.

“I have no recollection of that being said to me — none,” the Premier said. “I think the SDA’s policy is to withdraw all extended trading hours at Christmas. It would be fair to say they are disappointed in the policies I have taken on in relation to trading hours.”

He said the decision to reduce the number of 7am opening days was made because few shoppers took advantage of the extra hour.

Mr McGowan said big business had overreacted to the decision.

He said he had no plans to extend 11am to 5pm Sunday trading.

“That’s something we’re considering in the lead-up to the next election,” Mr McGowan said.

Mr O’Keeffe denied the threat and later changes showed the union had influence over the Premier.

“If the public were breaking down the doors, I’m sure he wouldn’t have done it,” Mr O’Keeffe said.